Sale of Energy, Chemicals and Resources ("ECR") Business - Income Statement Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 26, 2020	Jun. 28, 2019	Jun. 26, 2020	Jun. 28, 2019	Sep. 27, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other (expense) income, net		$ (2,000)		$ (14,800)
Net Earnings of the Group from Discontinued Operations	$ 18,043	435,684	$ 125,511	438,837
Worley | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	59	392,526	11,221	2,718,317
Direct cost of contracts	(69)	(340,525)	(6,124)	(2,336,076)
Gross profit	(10)	52,001	5,097	382,241
Selling, general and administrative expenses	(801)	(39,556)	43,359	(333,155)
Operating (Loss) Profit	(811)	12,445	48,456	49,086
Gain on sale of ECR business	31,456	917,697	113,366	917,697	$ 935,100
Other (expense) income, net		(7,864)		(40,158)
Other (expense) income, net	1,472		112
Earnings Before Taxes from Discontinued Operations	32,117	922,278	161,934	926,625
Income Tax Expense	(14,074)	(486,594)	(36,423)	(487,788)
Net Earnings of the Group from Discontinued Operations	$ 18,043	$ 435,684	$ 125,511	$ 438,837